1. Field of the Invention
The present invention relates to the field of aerial firefighting and, more specifically, to the field of air delivery systems for liquid or powder materials including those that might be used as fire suppressant materials.
2. Description of the Related Art
Aspects of the present invention relate to air delivery systems for firefighting suppressants such as water or fire retardant chemicals in liquid or powder form. The most prevalent current air delivery system for fire suppressant materials uses fixed or rotary wing aircraft to carry fire suppressant material to a target and release the fire suppressant material over the fire or other target. Fire suppressant materials such as water, Phos-Chek®, FIRE-TROL® or others can be delivered this way. Often the fire suppressant material is carried in an internal or external reservoir of the fixed or rotary wing aircraft, typically using a reservoir specifically modified for air distribution of such fire suppressant materials.
U.S. Pat. No. 7,009,029 to Cleary, et al., describes an example of an improved air delivery system for fire suppressant material. The Cleary patent describes the use of a plastic package (or “bomblet”) for carrying and delivering firefighting suppressant materials in a more controlled way. In the air delivery system described in the Cleary patent, the plastic packages are filled with fire suppressant materials, loaded on appropriate delivery aircraft for transport to the target and then the filled plastic packages are dropped on the target area. Use of the plastic packages allows the aircraft to deliver some or the entire load of filled plastic packages over one or more desired target areas. Significantly, use of the plastic packages allows the delivery aircraft to fly at a higher altitude when delivering the fire suppressant material while still providing more controlled placement of the fire suppressant material at the target.
The plastic packages described in the Cleary patent are sufficiently rigid as to be freestanding when filled and capable of being shipped empty, filled with suppressant material and stacked together with other filled packages in the hold of an aircraft. The plastic package is designed to hold a quantity of, for example, fifty pounds of fire suppressant material. The plastic package is designed with a weak seam so that, after being dropped from the airplane, a filled plastic package ruptures above the ground due to wind velocity or contact with trees or other above-ground objects.
A variation on the Cleary patent's plastic package for fire suppressant materials is illustrated in U.S. Patent Publication No. 2007/0090174 to Goddard. The Goddard publication describes a container for fire suppressant and similar materials with a larger capacity than the package of the Cleary patent but which is otherwise used in a manner similar to the Cleary patent package in delivering fire suppressant or other materials. The Goddard publication container is made up of a base, a sidewall assembly that is placed on the base and a top that can be held against the container formed of the base and sidewall by a straps. The Goddard publication container may be containerboard or corrugated containerboard. The Goddard publication container may also include a liquid impermeable polymer bag connected to the straps that extend from the top of the container into the container. If such a bag is included, the straps are heat welded to the bag.